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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    
    <script>
         var c,b;//全局变量
         b=c=0;
       function fun()
       {
          
          var a ;//局部变量
          a= b=c=9;
          console.log("a"+a)
          console.log("b"+b)
          console.log("c"+c)
       }

       fun();
          console.log("bb"+b)
          console.log("cc"+c)
          console.log("aa"+a)




    </script>
</body>
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